This Copic Multiliner Pen in Cobalt is a fine quality inking pen. The pigment-based ink is waterproof and won't bleed or smear when used with Copic Markers. These quick-drying pens are ideal for anime, illustration, cartooning, pen-and-ink drawing, scrapbooking, and other detail work. Copic's polyester nibs won't roll or bend, and they're housed in a durable plastic case with "click fit" caps that prevent dry-out. Perfect for hand lettering and calligraphy, their richly pigmented ink is great for dynamic writing both broad and narrow. Conforms to ASTM D-4236.